/*
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.kotlindemos

import android.graphics.Color
import android.graphics.Point
import android.location.Location
import android.os.Bundle
import android.view.View
import android.widget.AdapterView
import android.widget.ArrayAdapter
import android.widget.CheckBox
import android.widget.SeekBar
import android.widget.Spinner

import androidx.appcompat.app.AppCompatActivity

import com.google.android.gms.maps.CameraUpdateFactory
import com.google.android.gms.maps.GoogleMap
import com.google.android.gms.maps.OnMapReadyCallback
import com.google.android.gms.maps.SupportMapFragment
import com.google.android.gms.maps.model.BitmapDescriptorFactory
import com.google.android.gms.maps.model.Circle
import com.google.android.gms.maps.model.CircleOptions
import com.google.android.gms.maps.model.Dash
import com.google.android.gms.maps.model.Dot
import com.google.android.gms.maps.model.Gap
import com.google.android.gms.maps.model.LatLng
import com.google.android.gms.maps.model.Marker
import com.google.android.gms.maps.model.MarkerOptions
import com.google.android.gms.maps.model.PatternItem

import java.util.ArrayList
import java.util.Arrays

/**
 * This shows how to draw circles on a map.
 */
class CircleDemoActivity :
        AppCompatActivity(),
        SeekBar.OnSeekBarChangeListener,
        AdapterView.OnItemSelectedListener,
        OnMapReadyCallback {

    private val DEFAULT_RADIUS_METERS = 1000000.0

    private val MAX_WIDTH_PX = 50
    private val MAX_HUE_DEGREE = 360

    private val MAX_ALPHA = 255
    private val PATTERN_DASH_LENGTH = 100
    private val PATTERN_GAP_LENGTH = 200

    private val sydney = LatLng(-33.87365, 151.20689)

    private val dot = Dot()
    private val dash = Dash(PATTERN_DASH_LENGTH.toFloat())
    private val gap = Gap(PATTERN_GAP_LENGTH.toFloat())
    private val patternDotted = Arrays.asList(dot, gap)
    private val patternDashed = Arrays.asList(dash, gap)
    private val patternMixed = Arrays.asList(dot, gap, dot, dash, gap)

    // These are the options for stroke patterns
    private val patterns: List<Pair<Int, List<PatternItem>?>> = listOf(
            Pair(R.string.pattern_solid, null),
            Pair(R.string.pattern_dashed, patternDashed),
            Pair(R.string.pattern_dotted, patternDotted),
            Pair(R.string.pattern_mixed, patternMixed)
    )

    private lateinit var map: GoogleMap

    private val circles = ArrayList<DraggableCircle>(1)

    private var fillColorArgb : Int = 0
    private var strokeColorArgb: Int = 0

    private lateinit var fillHueBar: SeekBar
    private lateinit var fillAlphaBar: SeekBar
    private lateinit var strokeWidthBar: SeekBar
    private lateinit var strokeHueBar: SeekBar
    private lateinit var strokeAlphaBar: SeekBar
    private lateinit var strokePatternSpinner: Spinner
    private lateinit var clickabilityCheckbox: CheckBox

    /**
     * This class contains information about a circle, including its markers
     */
    private inner class DraggableCircle(center: LatLng, private var radiusMeters: Double) {
        private val centerMarker: Marker = map.addMarker(MarkerOptions().apply {
            position(center)
            draggable(true)
        })

        private val radiusMarker: Marker = map.addMarker(
                MarkerOptions().apply {
                    position(center.getPointAtDistance(radiusMeters))
                    icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE))
                    draggable(true)
                })

        private val circle: Circle = map.addCircle(
                CircleOptions().apply {
                    center(center)
                    radius(radiusMeters)
                    strokeWidth(strokeWidthBar.progress.toFloat())
                    strokeColor(strokeColorArgb)
                    fillColor(fillColorArgb)
                    clickable(clickabilityCheckbox.isChecked)
                    strokePattern(getSelectedPattern(strokePatternSpinner.selectedItemPosition))
                })

        fun onMarkerMoved(marker: Marker): Boolean {
            when (marker) {
                centerMarker -> {
                    circle.center = marker.position
                    radiusMarker.position = marker.position.getPointAtDistance(radiusMeters)
                }
                radiusMarker -> {
                    radiusMeters = centerMarker.position.distanceFrom(radiusMarker.position)
                    circle.radius = radiusMeters
                }
                else -> return false
            }
            return true
        }

        fun onStyleChange() {
            // [circle] is treated as implicit this inside the with block
            with(circle) {
                strokeWidth = strokeWidthBar.progress.toFloat()
                strokeColor = strokeColorArgb
                fillColor = fillColorArgb
            }
        }

        fun setStrokePattern(pattern: List<PatternItem>?) {
            circle.strokePattern = pattern
        }

        fun setClickable(clickable: Boolean) {
            circle.isClickable = clickable
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_circle_demo)

        // Set all the SeekBars
        fillHueBar = findViewById<SeekBar>(R.id.fillHueSeekBar).apply {
            max = MAX_HUE_DEGREE
            progress = MAX_HUE_DEGREE / 2
        }
        fillAlphaBar = findViewById<SeekBar>(R.id.fillAlphaSeekBar).apply {
            max = MAX_ALPHA
            progress = MAX_ALPHA / 2
        }
        strokeWidthBar = findViewById<SeekBar>(R.id.strokeWidthSeekBar).apply {
            max = MAX_WIDTH_PX
            progress = MAX_WIDTH_PX / 3
        }
        strokeHueBar = findViewById<SeekBar>(R.id.strokeHueSeekBar).apply {
            max = MAX_HUE_DEGREE
            progress = 0
        }
        strokeAlphaBar = findViewById<SeekBar>(R.id.strokeAlphaSeekBar).apply {
            max = MAX_ALPHA
            progress = MAX_ALPHA
        }

        strokePatternSpinner = findViewById<Spinner>(R.id.strokePatternSpinner).apply {
            adapter = ArrayAdapter(this@CircleDemoActivity,
                    android.R.layout.simple_spinner_item,
                    getResourceStrings())
        }

        clickabilityCheckbox = findViewById(R.id.toggleClickability)

        val mapFragment = supportFragmentManager.findFragmentById(R.id.map) as SupportMapFragment
        mapFragment.getMapAsync(this)
    }

    /** Get all the strings of patterns and return them as Array. */
    private fun getResourceStrings() = (patterns).map { getString(it.first) }.toTypedArray()

    /**
     * When the map is ready, move the camera to put the Circle in the middle of the screen,
     * create a circle in Sydney, and set the listeners for the map, circles, and SeekBars.
     */
    override fun onMapReady(googleMap: GoogleMap?) {
        map = googleMap ?: return
        // we need to initialise map before creating a circle
        with(map) {
            moveCamera(CameraUpdateFactory.newLatLngZoom(sydney, 4.0f))
            setContentDescription(getString(R.string.circle_demo_details))
            setOnMapLongClickListener { point ->
                // We know the center, let's place the outline at a point 3/4 along the view.
                val view: View = supportFragmentManager.findFragmentById(R.id.map)?.view
                        ?: return@setOnMapLongClickListener
                val radiusLatLng = map.projection.fromScreenLocation(
                        Point(view.height * 3 / 4, view.width * 3 / 4))
                // Create the circle.
                val newCircle = DraggableCircle(point, point.distanceFrom(radiusLatLng))
                circles.add(newCircle)
            }

            setOnMarkerDragListener(object : GoogleMap.OnMarkerDragListener {
                override fun onMarkerDragStart(marker: Marker) {
                    onMarkerMoved(marker)
                }

                override fun onMarkerDragEnd(marker: Marker) {
                    onMarkerMoved(marker)
                }

                override fun onMarkerDrag(marker: Marker) {
                    onMarkerMoved(marker)
                }
            })

            // Flip the red, green and blue components of the circle's stroke color.
            setOnCircleClickListener { c -> c.strokeColor = c.strokeColor xor 0x00ffffff }
        }

        fillColorArgb = Color.HSVToColor(fillAlphaBar.progress,
                floatArrayOf(fillHueBar.progress.toFloat(), 1f, 1f))
        strokeColorArgb = Color.HSVToColor(strokeAlphaBar.progress,
                floatArrayOf(strokeHueBar.progress.toFloat(), 1f, 1f))

        val circle = DraggableCircle(sydney, DEFAULT_RADIUS_METERS)
        circles.add(circle)

        // Set listeners for all the SeekBar
        fillHueBar.setOnSeekBarChangeListener(this)
        fillAlphaBar.setOnSeekBarChangeListener(this)

        strokeWidthBar.setOnSeekBarChangeListener(this)
        strokeHueBar.setOnSeekBarChangeListener(this)
        strokeAlphaBar.setOnSeekBarChangeListener(this)

        strokePatternSpinner.onItemSelectedListener = this
    }

    private fun getSelectedPattern(pos: Int): List<PatternItem>? = patterns[pos].second

    override fun onItemSelected(parent: AdapterView<*>, view: View, pos: Int, id: Long) {
        if (parent.id == R.id.strokePatternSpinner) {
            circles.map { it.setStrokePattern(getSelectedPattern(pos)) }
        }
    }

    override fun onNothingSelected(parent: AdapterView<*>) {
        // Don't do anything here.
    }

    override fun onStopTrackingTouch(seekBar: SeekBar) {
        // Don't do anything here.
    }

    override fun onStartTrackingTouch(seekBar: SeekBar) {
        // Don't do anything here.
    }

    override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
        // Update the fillColorArgb if the SeekBars for it is changed, otherwise keep the old value
        fillColorArgb = when (seekBar) {
            fillHueBar -> Color.HSVToColor(Color.alpha(fillColorArgb),
                    floatArrayOf(progress.toFloat(), 1f, 1f))
            fillAlphaBar -> Color.argb(progress, Color.red(fillColorArgb),
                    Color.green(fillColorArgb), Color.blue(fillColorArgb))
            else -> fillColorArgb
        }

        // Set the strokeColorArgb if the SeekBars for it is changed, otherwise keep the old value
        strokeColorArgb = when (seekBar) {
            strokeHueBar -> Color.HSVToColor(Color.alpha(strokeColorArgb),
                    floatArrayOf(progress.toFloat(), 1f, 1f))
            strokeAlphaBar -> Color.argb(progress, Color.red(strokeColorArgb),
                    Color.green(strokeColorArgb), Color.blue(strokeColorArgb))
            else -> strokeColorArgb
        }

        // Apply the style change to all the circles.
        circles.map { it.onStyleChange() }
    }

    private fun onMarkerMoved(marker: Marker) {
        circles.forEach { if (it.onMarkerMoved(marker)) return }
    }

    /** Listener for the Clickable CheckBox, to set if all the circles can be click */
    fun toggleClickability(view: View) {
        circles.map { it.setClickable((view as CheckBox).isChecked) }
    }
}

/**
 * Extension function to find the distance from this to another LatLng object
 */
private fun LatLng.distanceFrom(other: LatLng): Double {
    val result = FloatArray(1)
    Location.distanceBetween(latitude, longitude, other.latitude, other.longitude, result)
    return result[0].toDouble()
}

private fun LatLng.getPointAtDistance(distance: Double): LatLng {
    val radiusOfEarth = 6371009.0
    val radiusAngle = (Math.toDegrees(distance / radiusOfEarth)
            / Math.cos(Math.toRadians(latitude)))
    return LatLng(latitude, longitude + radiusAngle)
}